Small diameter sausages such as frankfurters or the like usually are made using food casings of cellulose. Cellulose food casings and the like customarily are manufactured in long continuous tubular lengths. For handling convenience, these long tubular lengths are gathered into pleats by shirring and are longitudinally compressed by known techniques to obtain a shorter, relatively rigid tubular element known in the industry as a shirred casing stick. The coherency of a shirred stick is derived in part from the shirring operation which forms the casing into generally conical pleats which nest one within another.
During a stuffing operation the stick is loaded onto a stuffing horn and a food emulsion is fed through the horn and into casing which is drawn forward from the stick by the stuffing pressure. It is not uncommon for a shirred stick 50 cm long to contain upwards of 50 meters or more of casing so a large number of individual frankfurters are made with each stick.
Packaging and shipping of shirred sticks presents several problems particularly for the type of casings used for frankfurters. These casings generally have a wall thickness of only about 0.025 mm to about 0.05 mm and shirred sticks of this casing are relatively fragile in that the nested pleats of casing formed by the shirring operation are easily separated or pulled apart. If the pleats separate, the stick is said to break or lose "coherency". The result is one or more rigid shirred sections connected by loose unshirred sections. Sticks in this condition are not easily loaded onto a stuffing horn and are not at all suitable for automatic stuffing operations wherein the stick is loaded onto a stuffing horn by mechanical means. Accordingly, the packaging for the shirred sticks must be able to minimize stick breakage.
Shirred sticks also are susceptible to damage if made wet. Since stuffing machines frequently are hosed down with water after a stuffing operation, any sticks in the area must be retained in packaging which provides a barrier to water spray and is not itself damaged by water contact.
In commercial practice it generally is customary to package sticks in tight bundles of fifty (50) sticks. Bundling sticks together accomplishes several functions. For example, a tight bundle helps to prevent bowing of individual sticks. Bowing is the result of a number of factors known in the art and is cause for concern because a bowed stick may not load onto a stuffing horn. A tight bundle further tends to reduce the likelihood of stick breakage as long as the bundle remains intact.
Conventional packaging for retaining a stick bundle generally is a carton or box comprising a combination of corrugated fiber board and a plastic wrap such as a shrink or stretch wrap. Corrugated fiber board cartons are substantially rigid and are recloseable so unused sticks remaining after a stuffing operation can be returned to the carton. Thus, if the stuffing operation consumes fewer than fifty sticks, the unused remaining sticks are usually loosely laid back into the carton. However, the returned sticks which are loose in the carton may bow and are more susceptible to damage. Also, the carton, when partly filled, takes up the same space as a full carton due to the rigidity of the corrugated fiber board. Corrugated fiber board has the further drawbacks of adding bulk and expense to the packaging and unless it is treated, the material is susceptible to water damage. The presence of corrugated fiber board dust in a food processing kitchen also is objectionable. Accordingly, it is not uncommon for a food process to unload such cartons outside the kitchen area and then carry loose casing sticks into the kitchen for use. In another packaging system as shown in U.S. Pat. No. 3,764,351, rigid end panels are placed against the end of the bundle and then the bundle is held together with the rigid end panels by a shrink film. The integrity of the resulting package is destroyed when the film is torn for opening the package.
Shirred sticks are sold in a number of different diameters and lengths. While packages of fifty sticks are most common, counts of less than fifty sticks are usual for certain sizes of casings. Accordingly, different sizes of cartons and/or carton components must be kept in inventory to provide the appropriate packaging for a given number of each particular size (diameter and length) of stick. The need to obtain and stockpile carton or carton components in a variety of sizes adds to the packaging costs.
U.S. Pat. No. 5,137,153 discloses a package of shirred sticks having a hexagonal-like cross section. The sticks are secured by a restraining means such as a wrap of paper, plastic film, net or bands which applies radial pressure to hold the sticks together. While the package as disclosed in this patent reduces the use of corrugated packaging material, it is not entirely satisfactory. For example, once the restraining means is opened, the structure lacks a repackaging feature so other accommodations must be made for storage of unused sticks.
Another prior art package, as disclosed in U.S. patent application Ser. No. 08/030,923, uses a heat shrinkable film to form a container in situ about a bundle of shirred sticks. Heat shrinking causes the film to assume the shape of the bundle and the resulting container encloses the bundle of sticks on all sides. Further, the container formed in this fashion is self supporting so after sticks are removed it still provides a receptacle into which unused sticks can be placed for storage.
While this packaging provides an alternative to conventional shirred stick packaging it has certain drawbacks. For example, when the film shrinks, it draws tight around the corners of the bundle. This has the effect of capturing the ends of individual sticks which could restrict dispensing from the container. Also, while heat shrinking to form a tight package is acceptable, exposure of the casing to heat shrinking temperatures is not preferred and the energy requirements for heat shrinking adds to the packaging costs.
The present invention provides a package which maintains the integrity of a bundle of shirred casing sticks without use of bulky corrugated fiberboard or the like and provides a method for forming the package which is less energy intensive than heat shrinking. Moreover, the package of the present invention encloses the bundle of sticks, opens easily and when open, allows sticks to dispense freely. After opening, the package retains its integrity so that unused sticks are easily returned to the package.
The package of the present invention includes a stack of shirred sticks bundled together by a plastic film which is transversely wrapped tightly about the bundle. This tight wrapping is accomplished preferably by using a stretch film and placing it in tension about the bundle. A tight wrap also can be accomplished using a shrink film where the film is more loosely disposed about the bundle and then heat shrunk to tighten it. In both cases, the film enwrapment exerts radial pressure on the stack to hold the bundle together and to prevent the movement of shirred sticks in the bundle one relative to another.
Opposite ends of the film overlap along the top of the bundle. The overlapped ends are united and held together by any suitable mechanical or adhesive connector to maintain the wrap in tension about the bundle. The connector, for purposes of the present invention, is releasable to permit easy opening of the package and is resealable to permit reclosing the package.
For example, a mechanical connector can take the form of interlocking male and female strips along the overlapped ends of the film. An adhesive bond also can be used as the connector to unite the ends of the film. The adhesive bond can be formed by any suitable single or double sided tape or by laying a bead of adhesive along one or both of the opposite edges so that one edge can releasably adhere to the other. If a double sided tape or bead of adhesive is used, it can be disposed between the overlapped ends so it is adhered to the outer surface of the underlayer of film and to the inner surface of the overlayer of film.
In a preferred arrangement, the connector is a single sided tape that extends along the length of the bundle and is adhered to the inner surface of both the overlayer and underlayer. The tape is located so one half its width is adhered to the inner surface of the underlayer. The other half of tape width extends out from under the edge of the underlayer. After the overlayer is pulled tight around the bundle, it is pressed down against, and adhered to, the exposed surface of the adhesive tape.
As an alternative, a single sided tape can be used which extends the full length of the bundle so one half the width of the adhesive surface is adhered to the outer surface of both the overlayer and underlay of film. This arrangement, while functional, is not preferred for several reasons. For example, this arrangement does not lend itself to incorporation of an easy open feature. Also, when the package is opened, the adhesive side of the tape is toward the casing sticks so the casings could come into contact with the adhesive when the casings are dispensed. Further, the tape on the outside of the package is susceptible to damage or partial removal when several such packages are all loaded into a common container. Moreover, to open the package, the tape for at least part of its length must be removed. Once removed from the package the tape is difficult to reuse unless care is taken to keep the tape from sticking to itself.
When disposed tight about the bundle, the length of the wrapping film is longer than the perimeter of the bundle of sticks so an end portion of the overlayer extends beyond the adhesive or mechanical connector to provide a loose flap of film material. This flap extends substantially the full length of the bundle. If a sufficient length of film is provided, this loose flap functions as a means to facilitate opening the package. In this respect, the flap is gripped and pulled to separate the connector so the package opens its full length. In the preferred arrangement noted above, an adhesive tape, being adhered along half its width to the underlayer, remains with the underlay and is not removed. After sticks are dispensed from the package, the connection between the overlayer and underlayer is reestablished to close the package. In the case of a mechanical connector, the interlocking members are aligned and pressed together to reunite them and close the wrap. Where the connector is an adhesive, the package is reclosed simply by drawing the overlayer back around the remaining sticks and pressing it down against the underlayer so the two adhere together.
If the width of the wrapping film is greater than the length of the bundle, the film can be gathered and closed around the bundle ends. In a preferred arrangement, the film is a heat-sealable film. Heat sealing to form an enclosure for the bundle can occur after the film is wrapped tightly about the bundle. To do this, the film wrapped around the bundle preferably is laid to a flat width at each end of the bundle and heat sealed. As an alternative, the film can be formed to a bottom or side sealed bag prior to loading with shirred sticks. In either case the film still is transversely pulled tight around the bundle to secure the sticks together by radial pressure and the open bag ends are overlapped so as to provide a loose flap along the length of the bundle, which, as noted above, is pulled to open the package. Another alternative is to form the film into the shape of a tube using the adhesive tape as a longitudinal seam and then insert the bundle of sticks into the tube. The ends of the tube are heat sealed to enclose the bundle. In each case as noted above, the container formed by the wrapping film is wide enough so that once the package is opened, the ends of the sticks are free of the film and can dispense freely.
The apparatus for forming the package requires a trough having a base and upstanding side walls. The included angle between the base and each side wall is 120.degree. so the walls diverge outwardly from the base. This trough forms the stack and supports the sticks until they are bundled together.
In conventional practice, there generally are fifty (50) sticks in each bundle. For most sizes of casing, fifty sticks of shirred casing will weigh about 15-25 pounds so this weight is convenient to lift manually. Of course the total stick count in a bundle may be reduced if the casing is a size where a bundle of fifty sticks is excessively heavy or the stick count may be increased if a bundle of fifty sticks is relatively light. U.S. Pat. No. 5,137,153 discloses arranging fifty (50) sticks in a bundle which is hexagonal-like in cross section, but is missing a stick at two diametrically opposite apexes. Thus, the bundle arrangement disclosed in the '153 Patent is two sticks short of completely filling out a hexagonal shape so there are vacancies at two locations about the periphery bundle. For purposes of the present invention, a hexagonal form is used so that the full count of fifty sticks are arranged in a hexagonal shape which has no voids about its periphery due to missing sticks. This provides a compact and stable packaging arrangement.
A preferred bundle shape is disclosed in copending U.S. patent application Ser. No. 08/030,923. The sticks in this bundle are arranged in seven (7) rows wherein the first five rows each contain one more stick than the row below, and the next two (2) rows each contain one less stick than the row below. In this configuration the fifth (5th) row contains the greatest number of sticks.
Assembling the sticks into the desired bundle shape may be accomplished by loading sticks into a trough so the longitudinal axes of the sticks are parallel and the ends of the sticks are generally coplanar. The sticks first will cover the base of the trough between the side walls and this forms a first row of sticks. Preferably, the width of the trough base is selected so only five sticks are accommodated in the first row between the side walls. Sticks which are next loaded into the trough generally will arrange themselves one against another and against the trough walls until the trough is filled or until a desired number of rows has accumulated. With the walls arranged as noted above, the sticks in each row will number one more than the row below. After the fifth row, which will contain nine (9) sticks, the next two rows are arranged so there is one less stick in each row than the row below. This may require some manual manipulation of the sticks. For example, should the sixth row fill out to a full ten (10) sticks, then two of these sticks must be relocated to the seventh row to provide a stack which in transverse cross section is a hexagon. The top row of the stack of such configuration contains only seven (7) sticks and is parallel to the base of the trough. The stack can then be pushed from the trough and wrapped in film which is pulled tight around the stack. The ends of the film are overlapped and releasably bonded together as noted above. Portions of the wrapping film then are closed over the ends of the bundle to form a bag. As an alternative, the wrap can be laid into the trough before loading in the sticks and then pulled tight around the stack in the trough. Also, rather than sealing the ends of the wrap as a last step to form a bag, the sticks can be laid directly into a preformed bag draped in the trough.
Accordingly, the package of tubular shirred sticks of food casing of the present invention is characterized by:
a) a plurality of tubular shirred sticks of food casing all of substantially equal length and diameter arranged in a stack with the longitudinal axes of the sticks parallel and the stick ends coplanar, the sticks being arranged in rows piled one on another with the number of rows and sticks in each row being selected such that the stack has a desired shape in transverse cross section; PA1 b) a retainer disposed in tension transversely around the stack and pressing radially inward against the periphery of the stack for bundling the sticks together and securing the desired shape of the stack, the retainer having an inner surface disposed against the stack periphery and an outer surface; PA1 c) the retainer having opposite ends which overlap along one side of the stack, the overlapped ends defining an underlayer portion against the stack periphery and an overlayer portion superimposed on the underlayer; PA1 d) connector means releasably uniting said opposite ends, said connector means being in contact with the inner surface of the overlayer and with the underlayer to provide a releasable bond for holding the opposite ends of the retainer together and maintaining the retainer in tension about the stack; and PA1 e) the overlayer portion having an outer margin which is free of said connector means and loose from the underlayer, and the outer margin comprising means for grasping and pulling the overlayer for separating said connector means to open the package. PA1 a) arranging a plurality of tubular shirred sticks of food casing, each of generally the same length and diameter, in a stack with the longitudinal axes of the sticks parallel and the stick ends coplanar, the stack having a desired shape in transverse in cross section; PA1 b) disposing a retainer in tension transversely around the stack to exert a radial inward pressure on the stack for bundling the sticks together, the retainer having an inner surface disposed against the stack periphery and an outer surface; PA1 c) overlapping opposite ends of the retainer, the overlapped ends defining an underlayer portion against the stack and an overlayer portion superimposed on the underlayer; PA1 d) releasably connecting the inner surface of the overlayer to the underlayer for holding the opposite ends of the retainer together and maintaining the retainer in tension about the stack; and PA1 e) providing an outer margin of the overlayer which is free and loose from the underlayer, the outer margin comprising means for grasping and pulling the overlayer and separating it from the underlayer to open the package.
In another aspect, the present invention is characterized by a packaging method comprising the steps of: